Electromagnetic brake



Nov. 16 1926. 1,606,745

E. M. BOUTON Y ELECTROMAGNETIC BRAKE Filed Jan. 5. 1920 2 Sheets-Shea*u 1 j?? la! 1 .l

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E. M. BOUTON ELECTROMAGNETI'C BRAKE Filed Jan. 5. 1920 2 Sheets-Sheet 2 w|TNEssEs INVENTOR Patented Nov. 16, i926.A

UNITED sTATEs PATENT OFFICE.-v

EDGAB. M. BOUTON, or WILKINSBURG, PENNSYLVANIA, AssIGNOn To wEsTING- HOUSE ELECTRIC: a MANUFACTURING COMPANY, A CORPORATION or PnN'NsYL- VANIA.

ELECTROMAGNETC 'IBAKE Application led January 3, 1920. Serial No. 349,308.

electromagnets maybe utilized to perform` useful work.'

A second object of my invention is to pro- .0 vide a mechanism of the above-indicated character in which the usual brake shoes that are mounted for movements independent of their actuatin levers are vactuated Yin both directions by t e levers.

A further object -of my invention is to provide an electroma et so constructed that its arts may be readily'detached and assembled) for purposes of ins ection and repair. In the construction o brakes ofthe same '.0 general character as that ofthe mechanism covered by the present application, it has been customary to provide one or more magnetic circuits having'v air gaps between therespective ends of the core members and co- Il acting portions of the lever arms. In other arrangements, two movable core members attached to the respective levers have an air gap in approximately the central portion of the ener izing coil. In each of the aboveo describe arrangements, it is/possible for the I leakage flux to traverse paths which do not comprise air gaps between re atively movable parts. Such flux does not,th'erefore, perform any useful work and the-eiiiciency` of 5 Vthe electromagnet is impaired to a degree corres onding to the value'of such flux.

In t e present arrangement, I rovide an' electroma et having two paralle magnetic circuits, t e core member constituting thelcommon portio'nofthe magnetic circuits; Thel lever 'arms of4 therbrake are bifurcated at their respective u per ends to provide arms which extend ad) acent'toopposite sides of the magnet coil. The members of each pair of o sitely-extending arms are in' substantial adiement and havean air gap between their adjacent ends that lis adjacent to the central portion of the coil.

It will be apparent that, inthe arrange- 0 ment described above, any leakage `flux traversingpaths constituting portions of the coil and the Oppositely-textending arms must" traverse the air gaps between the arms. Accordingly, when the coil in energized, the

leakage flux traversing the air gaps between 'relatively movable parts produces 'forces which assist those exerted by the core member'l to actuate the levers. l v L AnotherV feature of my invention resides v'in' the' provision of means whereby the brake shoes, which are pivotally mounted for movements independent of the brake levers, are actuated into enga ement by the brake levers and are actuate `by the force of gravity assisted by electro'. magnetic forces exerted by energized portions of the levers. The `llatter force isproduced by reason of the fact that a portion .of the useful flux of the brake traverses a path comirising thebrake levers, the brakeholeis an a portion of the I,frame of the ra e.

.Brakes of the prior-'art have been so constructed as to render it necessary toy practically dismantle the `brake mechanism inl order to remove the coil andvits core member foithe purposes of inspection and repair. This procedure was rendered necessary by the fact that the coil could only be removed through openings inthe supportingstructure adJacent to the ends of the coil.

In the embodiment of my invention, I provide supporting means of non-magnetizable material adjacent to the ends of the coil comprismg portions of the brake frame and re,- movable members of magnetizable material secured to the ends of the core members b means of bolts that are inserted longitudine 'ly with respect to the axis of the coil. By

' means of `this arrangement, itis onlynecessary to remove the securing bolts whereupon the coil and its core member may be removed by lifting upwardly without disturbing any pf the remaining parts of the brake strucure.

In the accompanying drawings, Fig. 1 is an end view of an electromagnetic brake constructed in accordancewitli m invention; FigxQ is a view partiallyin e evation and vpartially in longitudinal section, of the core lmember and its supporting means; Fig. 3 is a view in lon itudinal section taken on line III--III of 1 ig. l; and Fig. 4 is a top plan view of the mechanism of Fig. y.1.

`Reileiring to the drawings,V a .brakev wheel out of engagement l1 is mounted on a shaft 2 which may, for

are ivotall supported at 5. Each of the le vers contro a brake shoe 6 which` is pivotally sup orted at 7. Each of the levers l 'is provide.

with an adjustable stud 8 for engaging the corresponding .brake shoe to actuate 1t to its operative position.

The respective levers are retained in such positions as to effect the engagement of the b rake shoes withthe wheel l by means of springs 9 and a rod 10 for connecting the f outer ends of the springs. The upper portions of thelevers 4 are bifurcated to form members 11 of substantially U-shape, the arms '1la of the bifurcated members extending inwardly toward each other, but having air gaps 12 therebetween. The levers are controlled by an electromagnet comprising a substantially cylindrical core member 13 and Ia. coil 14. The core member 13 is supported b a stationary bracket 14a, of non-magnetizalyile material, havin upwardly-extending flanges 15 and 16. ach of the ianges 15 and 16 is provided with a central opening 17 corresponding in size and shape to the cross section of the core member. The core member 13 is retained in osition by means of members 18 of magnetizable material, which comprise two concentric disks,'the smaller of which is disposed within the openings in the flanges and the larger of which covers-and surrounds the openings. Bolts `19, also of magnetizable material, rigidly secure the core member 13 to the member 18. The levers 4 are recessed and do not mechanically engage the bolt heads.

It may be assumed that the brake wheel 1 is'at rest and that the several parts of the brake mechanism occupy their respective illustrated positions to maintain the brake wheel at rest. In case' it is desired to operate vthe mechanism to which the brake wheel 1 is connected, the coil 14 of the brake magnet is energized by closing its circuit by any suitable means (not shown). The core member 13 is energized `to attract the adjacent portions of the lever arms to actuate the levers about their points of pivotal support in opposition to the forces of the springs 10. The studs 8 are moved outwardly to releasei the brake shoes 6 and the latter are permitted to be moved outwardly by the force of gravity assisted by electromagnetic forces, as will be hereinafterV described. The opening of the circuit of the coil 14 de-energizes the magnet and the springs actuate the several parts to their initial positions.

4It. is well known that,I when the coil of electromagnets are energized to relatively high degrees, considerable flux traverses leakage paths including side portions of the coil and such magnetizable material as may be adjacent to the sides of the coil. In case the magnetic circuits traversed by the leakage flux does not comprise parts that are relatively movable during the operation of the magnet, no useful work is performed by such leakage flux. Such magnet is, therefore, inefficient and must be of greater size and contain larger quantities of material than are necessar in case theleakage flux is utilized to assist the force of the main magnetic circuit.

Lach of the air gaps adjacent to the central portion of the coil 14 is traversed by such leakage flux as may emanate from the opposite s idesof the coil and traverse various portions of the arms. Thus, when the coil is energized, considerable forces, due to leakage flux, are exerted across the air gaps 12- and these forces assist those exerted by the flux in the normal paths at the air gaps 12 and at the ends of the core member 13 to actuate the brake levers.

An additional path for lux'of the coil 14 comprises the levels 4, the studs 8, brake shoes 6 and the base portion of the frame 3. The effect of the energization of the leakage path just described is to cause the studs 8 to exert forcesuponthe brake shoes 6 which assist the force of gravity and thereby eiect i the quick separation of the brake shoes and the wheel 1 when the levers 4 are actuated to release the brakes.

In case it becomes necessary or advisable to inspect or repairy the magnet structure, it l is only necessary to remove the bolts 19, whereupon the core member 13 and the coil 14 may be removed upwardly without disturbin the position of the arrangement or any o the associated parts. The core mem- 1 ber and the coil may be replaced by reversingthe operation just described.

umerous advantages result from the employment of a brake mechanism constructed and arranged in the manner described above. l The electromagnet structure may be materially smaller than those of the prior art by reason of its more efficient operation. The rotating parts controlled by brakes of this character may be released more quickly than 1 is possible in such arrangements as rovide for the release of the wheel by the orce 'of gravity alone. The various parts of the brake mechanism, particularly the structure of the electromagnet, may be easily and l quickly assembled or removed whenever the occasion so demands. A

The coil contains no moving parts which necessitate the rovisionof guide members and which are requently a source of injury I to the insulation in the interior of the coil.

I claim as my invention:

1. The combination with 'a coil of substantially-cylindrical Shape, of supporting means therefor comprising a stationary meml;

berhaving portions respectively extending l adjacent to the opposite ends of said coil,

and means comprising pole pieces and members axially movable relatively to said coil for securing the latter in position and for securing the pole pieces to said coil and to said stationary member.

2. The combination with a. coil of substantially cylindrical shape, of supporting means therefor comprising members extending adjacent to the respective ends of said coil, and means for securing said coil to said members, said means comprising pole l'pieces and members for securing said pole pieces to said coil, said securing members being movable axially relatively to said coil, whereby said coil may,

upon removal of said securing means, be actuated laterally from its normal position.

3. The combination with a coil of substantially cylindrical shape and` a core member therefor, of members extending adjacent to the respective ends of said core member and having openings therein, of members constituting pole piecesior said core disposed Within Vsaid openings, and means movable axially relatively to said coil for securing said pole pieces to said core member. p

In testlmo'ny whereof, I have hereunto subscribed my name this 17th day of De cember, 1919.

EDGAR M. BOUTON. 

